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561drift [2015/01/22 09:42] (current)
n1eu created
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 +**Correcting Frequency Drift caused by dirty Offset Pot**
 +
 +Watching the PSK waterfall, the incoming signal drifts off and
 +my software can,t decode it.  Sometimes it comes back, sometimes I have to
 +chase the signal. ​ I don't know if it is doing the same on transmit. ​ The
 +frequency readout is not showing any change when this happens. ​ The
 +problem with the PSK reception seems to be limited to 20 meters. ​ On a long
 +winded ragchew with my slow typing, I have had a few people tell me that I
 +drift a wee bit.  On 10, 15, or 40 meters I am not having this trouble. (KM4FO)
 +----------------
 +When I had my Corsair 2, I had a warble on a number of the HF bands. I could clearly see it on PSK31 signals on the waterfall of MixW. I rebuilt the PTO a number of times but it didn't cure the problem.
 +
 +Eventually it was traced to a dirty preset pot which set an offset voltage on those bands. I can't remember the component reference, but - if I remember right - it was the only one on the board and sat up at right angles to the board. A squirt of switch cleaner did the trick.
 +
 +For you, this may be the cause of your problem. Anyway, if you can find the offset pot, give it a squirt of switch cleaner and see what happens! (MM0RKT)
 +----------------
 +Sprayed R29 on the oscillator mixer board, closed back up, hooked back up and bingo! (KM4FO)
  

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